Burner

ABSTRACT

A burner, particularly for use with a poultry brooder, is supported on a burner pan and comprises a separable nozzle and mixing chamber, the nozzle having a tapered reduced throat and the mixing chamber being enlarged and having air inlets about its periphery. A reduced portion of the nozzle fits within the upper end of the mixing chamber and the nozzle and the mixing chamber grasp the burner pan between them. A fitting with an orifice is secured in the bottom of the mixing chamber for the gas supply.

United States Patent [191 Schell [4 Oct. 16, 1973 BURNER [75] Inventor: Orville C. Schell, Rogers, Ark.

[73] Assignee: Hoyt Corporation, Rogers, Ark.

[22] Filed: Dec. 20, 1971 21 Appl. No.: 209,632

[52] US. Cl 239/426, 119/32, 239/431 [51] Int. Cl .1 B051) 7/12 [58] Field of Search 239/419, 419.3, 419.5, 239/426, 430, 431; 119/32 [56] References Cited UNITED STATES PATENTS 3,333,775 8/1967 Van De Roer 239/4195 X 3,319,693 5/1967 Bryant et al. 119/32 X 3,260,465 7/1966 Grumbein..... 239/4195 X 3,349,752 10/1967 Murphy 119/32 Thomas et al. 239/420 X 2,366,605 l/l945 Evans 239/430 X 3,498,545 3/1970 Short 239/430 X 3,505,976 4/1970 Miller 119/32 Primary Examiner-M. Henson Wood, Jr. Assistant Examiner-Michael Y. Mar Attorney-Irvin S. Thompson et a1.

[5 7] ABSTRACT A burner, particularly for use with a poultry brooder, is supported on a burner pan and comprises a separable nozzle and mixing chamber, the nozzle having a tapered reduced throat and the mixing chamber being enlarged and having air inlets about its periphery. A reduced portion of the nozzle fits within the upper end of the mixing chamber and the nozzle and the mixing chamber grasp the burner pan between them. A fitting with an orifice is secured in the bottom of the mixing chamber for the gas supply.

1 Claim, 4 Drawing Figures BURNER The present invention relates to burners, more particularly of the type that are adapted for use in poultry brooders, such as that shown in U.S. Pat. No. 3,505,976, Apr. 14, 1970.

In the past, when designing burners of this type, it has been necessary to provide a cluster of relatively small burners in order to achieve both the necessary heating capacity and also the necessary combustion efficiency. The use of a single relatively large burner or jet has led to incomplete combustion, because the gas stream has been of such volume and velocity that the gas is not mixed adequately with theair. Evidently, the primary air has tended to flow largely parallel to the gas stream within the burner and hence to undergo only incomplete mixture with the gas, with the result that the gas is only partially burned upon emerging from the nozzle of the burner.

Accordingly, it is an object of the present invention to provide a burner which need be embodied in only a single jet even for a relatively large gas flow, and which will nevertheless ensure virtually complete burning of the gas.

Another object of the present invention is the provision of a burner whose parts have improved protection from the flame.

Finally, it is an object of the present invention to provide a burner which will be relatively simple and inexpensive to manufacture, easy to assemble, install, maintain and repair, and rugged, durable and reliable in use.

Other objects and advantages of the present invention will become apparent from a consideration of the following description, taken in connection with the accompanying drawing, in which:

FIG. 1 is a perspective view, with parts broken away, showing the burner of the present invention in the environment of a poultry brooder;

FIG. 2 is an enlarged fragmentary cross-sectional view of the burner of the present invention;

FIG. 3 is an exploded assembly view of the burner; and

FIG. 4 is a fragmentary perspective view of the burner with its associated pilot and temperature control.

Referring now to the drawing in greater detail, there is shown a burner according to the present invention, in the environment of a poultry brooder having a downwardly concave ribbed hood 1 of sheet metal or the like, which is suspended by hangers 3 from the ceiling of the building (not shown). Hangers 3 are secured at their lower ends to the upper ends of legs 5 which penetrate the top of hood 1. Legs 5, in turn, support a radiant 7 of conventional construction, by which the heat of the flame is largely converted to radiant heat, and at their lower ends support a burner pan 9 which serves as the support for the burner 11, the pilot l3 and the thermally responsivedevice 15. The pilot 13 receives gas through a conduit 17 from a gas supply conduit 19. The burner 11 receives gaseous fuel through a conduit 21 controlled by a valve 23, from gas supply conduit 19. Thermally responsive device communicates through a conduit 25 with valve 23 to control valve 23 so as to close valve 23 when thermally responsive device 15 indicates a low temperature, that is, when the pilot 13 is unlighted, so that burner 11 cannot be supplied with gas when the pilot is out. Apart from this, the

of intersection between portion 43 and tapered gas supply to burner 11 may be automatically or manually controlled as desired, in any conventional way. Similarly, the structure of the pilot 1'3 and the thermally responsive device 15 may be conventional and need not be described in greater detail.

Turning now to the novel structure of the burner 11, it will be seen from FIGS. 2-4 that the burner has four principal portions: the nozzle 27, the mixing chamber 29, the orifice 31, and the connection nipple 33 by which the burner is interconnected to the conduit 21. To this end, the nipple 33 may be screw-threaded at both its ends for connection with the mixing chamber 29 and conduit 21 by reception in a screw-threaded axial opening through the bottom of chamber 29, the orifice 31 being externally screw-threaded and being disposed in the same end of nipple 33 that engages mixing chamber 29, the nipple 33 being internally screwthreaded at this end for this purpose, thereby to permit ready removal and replacement with a new orifice 31 or an orifice of a different size.

The crux of the invention, however, is the structure and arrangement of the nozzle 27 and mixing chamber 29, and the relationship of these parts to each other and to the burner pan 9. Thus, the nozzle 27 has an upper portion 35 of cylindrical outer contour that contains a reduced cylindrical bore 37 that terminates downwardly in a conically tapered bore 39. The cylindrical outer surface of portion 35 terminates downwardly in an annular downwardly facing abutment shoulder 41 that connects portion 35 with a reduced portion 43 of cylindrical outer contour, which in turn terminates downwardly in a sharp circular edge 45 that is the line bore Mixing chamber 29 has an enlarged cylindrical bore 47 therein which is of substantially the same internal diameter as the external diameter of portion 43 of nozzle 27, so that portion 43 has a sliding fit or force fit in bore 47. At its upper end, mixing chamber 29 terminates in a flat annular abutment shoulder 49 which is the upper edge of mixing chamber 29. At its lower end, mixing chamber 29 has an internally screw-threaded inwardly extending flange 51 which receives the upper end of nipple 33. Adjacent the lower end of bore 47, mixing chamber 29 has a plurality of peripherally spaced air inlets 53 of a diameter several times the distance between adjacent inlets. Adjacent its upper end, mixing chamber 29 has a small internally threaded hole 55 for the reception of a set screw 57 by which the parts of the burner may be secured together in the position of FIGS. 2 and 4.

Alternatively, nozzle 27 and mixing chamber 29 may interfit with a force fit or by mutually engaging screw threads.

The assembled condition of the parts is shown in FIG. 2, in which will be seen that the nozzle 27 is largely above the burner pan 9, while the mixing chamber 29 is entirely below the burner pan 9. The abutment shoulders 41 on nozzle 27 and 49 on mixing chamber 29 grasp between them the edge of the burner pan 9, which for this purpose has a hole substantially centrally therein of the same size as the external diameter of portion 43 of nozzle 27, thereby to receive and locate the latter.

There is thus provided a construction in which the gas enters from the gas orifice 31 axially of the mixing chamber 29, but the region of themixing chamber that is entered by the gas is of maximum diameter and is the 7 region that contains the air inlets 53. The flowing gas stream draws air in through inlets 53. The gas and air are thereafter progressively urged radially inwardly by the tapered bore 39, and then pass through the reduced cylindrical bore 37 and emerge from nozzle 27 and burn.

The air entering through inlets 53 thus has a substantially greater component of radially inward movement than air would have if the mixing chamber and the bores 37 and 39 all had a common cylindrical contour. Mixing of the air in the gas stream is accordingly promoted, as is proven by the fact that the flame of a burner according to the present invention is all blue; whereas a flame of a burner operated under comparable conditions but whose mixing chamber was entirely cylindrical throughout is at least partly yellow.

From a consideration of the foregoing disclosure, therefore, it will be evident that all of the initially recited objects of the present invention have been achieved.

Although the present invention has been described and illustrated in connection with a preferred embodiment, it is to be understood that modifications and variations may be resorted to without departing from the spirit of the invention, as those skilled in this art will readily understand. Such modifications and variations are considered to be within the purview and scope of the present invention as defined by the appended claims.

Having described my invention, I claim:

1. A burner having a mixing chamber, air inlets disposed about the mixing chamber and extending through the side walls of the mixing chamber and confronting each other across the mixing chamber, a gas inlet having an outlet disposed below said air inlets to supply combustible gas to the bottom of the mixing chamber, the burner terminating in a nozzle from which the mixture of air and gas emerges, the mixing chamber adjacent the air inlets having a greater diameter than adjacent the point of emergence of the mixture from the nozzle, said nozzle and mixing chamber being two separable pieces, said nozzle interfitting within an end of said mixing chamber, said nozzle having an annular abutment shoulder that faces said mixing chamber when said nozzle is interfitted within said mixing chamber, and a burner pan clamped between said abutment shoulder and the adjacent end of said mixing chamber, said nozzle having a cylindrical portion having a tapered inner contour receivable within said mixing chamber, said nozzle having a cylindrical bore that terminates in said tapered contour, said tapered contour and the outer surface of said cylindrical portion meeting in a sharp circular edge, said nozzle being above said pan and said mixing chamber being below said pan. 

1. A burner having a mixing chamber, air inlets disposed about the mixing chamber and extending through the side walls of the mixing chamber and confronting each other across the mixing chamber, a gas inlet having an outlet disposed below said air inlets to supply combustible gas to the bottom of the mixing chamber, the burner terminating in a nozzle from which the mixture of air and gas emerges, the mixing chamber adjacent the air inlets having a greater diameter than adjacent the point of emergence of the mixture from the nozzle, said nozzle and mixing chamber being two separable pieces, said nozzle interfitting within an end of said mixing chamber, said nozzle having an annular abutment shoulder that faces said mixing chamber when said nozzle is interfitted within said mixing chamber, and a burner pan clamped between said abutment shoulder and the adjacent end of said mixing chamber, said nozzle having a cylindrical portion having a tapered inner contour receivable within said mixing chamber, said nozzle having a cylindrical bore that terminates in said tapered contour, said tapered contour and the outer surface of said cylindrical portion meeting in a sharp circular edge, said nozzle being above said pan and said mixing chamber being below said pan. 